Pneumatic thermostat



C. E. BONNET. PNEUMATIC THERMOSTAT.

APPLICATION FILED NOV. 23. 1916.

1,365,812. Patented Jan. 18, 1921.

UNITED STATES PATENT OFFICE.

CHARLES E. BONNET, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO, THE. BISHOP-BABCOCK-BECKER COMPANY, OF CLEVELAND,

OHIO, A CORPORATION OF OHIO.

I PNEUMATIC THERMOSTAT.

Specification of Letters Patent.

Patented Jan. 18 1921.

Application filed November 23, 1916. Serial No. 133,085.

To all whom it may concern:

Be it known that I, CHARLES E. BONNET, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in Pneumatic Thermostats, of which the following is a specification.

My invention relates to thermostatic devices for regulating and preserving desired temperatures at points or areas in which such structure may be located; and the object of my invention is to provide a structure operable by means of compressed air which is arranged to control a motor in accordance with variable movement of a thermostatic element.

My present invention comprises a structure in the nature of animprovement upon the structure disclosed in my'Patent No. 974,743, dated November 1, 1910.

As hereinafter described, my invention comprises a chambered casing connected between a source of compressed air and a temperature-controlling motor; the latter being, for instance, a diaphragm valve on a steam radiator in a room where the thermostat may be located, or a spring-pressed diaphragm operativelyconnected with a damper in a pipe supplying hot air to said room; said casing having oppositely disposed ports which may have conical valve seats, respectively arranged to admit compressed air to said temperature controlling motor and e);- haust it from said motor to the atmosphere.

A double needle valve, which may have opposite conical ends, is fitted to saidports so that in accordance with the reciprocatory movement of said valve, said ports are alternately opened and closed; air being admitted to operate said motor when the valve is moved in one direction, and when said valve is moved inthe opposite direction. the motor air is exhaustedto permit'reverse movementof said motor; the movement of said valve being. effected in one direction by the thermostatic element and in the opposite direction by a spring.

These and other features of'my invention are more fully described hereinafter, reference being had to the accompanying drawin s, in which:

igure 1, is a front elevation of my improved thermostatic structure, showing its protective shell or casing in section.

Fig. 2, is aside elevation, partly in section, on the line II-'-II, Fig. 1.

Fig. 3, is a sectional plan view on the line III-III, Fig. 2, and

Fig. 4, is a plan view on the line IVIV, Fig. 2.

In the drawings, 1 represents a suitable backing plate or support which may be attached. to a wall 2 in any suitable manner, and is designed to support the thermostatic structure. This plate has a rearwardly extending portion 3 set into the wall and formingarecess 3 for a purpose to be described. Carried by the plate 1 is a supporting member or bracket 4 having a lower rearwardly extending portion 5 adapted to the recess 3 of the wall plate 1, said rearwardly extending portion being hollow and providing a chamber 6 for a purpose to be described; said chamber having ports or passages 7, 7 and 7", for the passage of air.

The bracket 4 has forwardly projecting shelves or extensions 8 and 9 at top and bottom of the same, between which a thermostatic element in the form of a tube 10 is mounted; the lower shelf having an adjustable screw 11 with a concaved upper end forming a seat 12 to receive apivot or bearing pin 13 at the lower end of said tube. At its upper end, the tube is provided with a pivot or bearing pin 13 adapted to seat in a conical recess 14 formed in an arm 15 of a lever 16, which lever is pivotally mounted on a pin 17 mounted or journaled in said upper shelf 8; the depending portion of said lever being connected with the bracket 4 by means of a spring 18 whereby it is normally held toward the bracket 4 against. the in fluence of the thermostatic element 10 tend ing to move it away from the same.

The ports or passages 7 and 7 of'the chamber 6 are respectively in communication with said source of compressed air and motor, and said chamber 6 has, opposite the inlet port or passage 7 an exhaust port 7 formed in an adjustable screw threaded plug 19, whereby the spaced relation of the valve seats of said ports or passages 7 and 7 may be adjust-ably predetermined as may be de sired.

Within the chamber 6 a double needle valve 20 is mounted in line with the ports 7 and 7 in the opposite walls of said chamber; said valve having oppositely disposed ends with beveled engaging portions and. 20 fitting the seats of said ports so that in accordance with reciprocatory movement of said valve, said ports are alternately opened and closed. One end of said valve 20 projects through the port 7 into contact with the lever 16; being provided with a spring 21 tending to move it in that direction. The

lever 16 is arranged to move the valve 20 to close the inlet port 7., under pressure of the spring 18. The spring 21 which tends to shift the valve 20 to close the exhaust port 7 is weaker than the spring 18 holding the lever in contact with said valve so that when the spring 18 is unrestrained the port 7 f the chamber 6' is closed by the opposite end of the valve 20 under the influence of the lever 16. Leading from said chamber 6 is a port or passage 7 for delivery to the motor of air entering via the port 7.

The stronger spring 18, of course, is restrained to permit the spring 21 to move the valve 20 and close the port 7" by the thermostatic element, which may consist of a hard rubber tube 10 disposed between the seat 14 in the arm 15 of the lever 16, and the seat 12 formed in the adjustable screw 11 carried by the lower shelf 9.

The thermostatic tube is vertically adjustable in its relation to the lever 16 and spring 18; the screw 11 in which the pivot pin 13 of said tube seats being conveniently raised and lowered for this purpose by turning the same in the threaded opening in the shelf 9. hen set for use, this screw may be raised or lowered as may be desired to increase or decrease the temperature at which the thermostat will act by an index arm 25, which is detaehably secured to said screw 11 in any suitable manner, as by a set screw 26. The free end of the arm extends to the edge of the shelf 9 and has an index pointer 27 in cooperative relation with a suitable scale 28 of temperature gradnations upon the edge of said base shelf, so

proportioned and arranged that said valve 20 may be caused to operate at different tem peratures in accordance with the adjustment of the arm 25, which controls the position of the seat 12, with respect to said temperature scale.

The bracket 4: may be secured to the wall plate 3 at the recessed portion of the latter by means of screws 29 which pass through the walls of said bracket adjacent the chamher 6; a gasket 30, usually of rubber, being interposed between the casing of the bracket 4 and the wall plate 3. The wall plate is provided with openings 31 and 31 formed in threaded nipples 32 and 82 projecting rearwardly therefrom and in line with the casing ports 7 and 7 The openings 31 and 31 are threaded and are also provided with seats 33 and 33 for needle valves 34; and 34", which regulate or control the amount of compressed air admitted to the chamber (3 through the port or passage 7, or discharged therefrom through the port or passage '7.

Suitable tubes 35 and 35 for the conveyance of air from the source of supply and to and from the motor are connected with these nipples and for this purpose connecting members 66 and ac may he provided. which are held to the nipples by gland nuts 3? and 3? of the usual form. with washers 3S and 38 of lead or other suitable material interposed between the same and the ends of the nipples. The needle valves 34- and 3% have threaded portions adapted to the threaded portions of the o ieuings $3.. and 31 and they are slotted at 59 and 2&9 for the free passage of air past the threaded portion.

By preference, the air is strained through gauze or fabric diaphragms ll) interposed between the wall. plate and the gasket; such wall plate being provided with annular ridges il around the openings 3:5 and 32". forming seats receiving the gauze mfabric washers.

As may be seen, it is a very simple matter to adjust the needle valves 34- and 34;" controlling the passage of air to and from the chamber 6, by simply turning the threaded portion of the same in the threaded portions of the openings 31 and 31;

The shelves 8 and 9 carried by the body plate may be maintained in rigid position with respect to each other'to permit reaction of the thermostatic element upon the lever 16 pivoted in said upper shel f, by means of rods +22 held in proper position by lock nuts 43 The whole construction is particularly compact, and is highly eilicient for the pur pose described.

The structure is preferaliily inclosed in a suitable casing 45. which may be of some suitable reticulated form whereby the parts of the structure are protected against tam- }:sering, and at the .ame time access of hear to effect the operation of the thern'iostal'ic tube is not impaired. This casing may carry a thermometer tube 41:6 with. scale 47.

l ly improved device operates as follows: Tn the position shown in the drawings. the exhaust port '7" being open and the inlet port 7 being closed, admission o l compressed air through the tubes to the temperature controllinomotor connected with the latter is cut oil"; holding said motor in the desired position to maintain the temperature corre- SijOllm'liDg with the position of the controlling lever 25. However, if the temperature in the room containing said device ris s. said tube 10 lengthens and shifts the lever 16: releasing the valve 20 and pcrmittiuathe same to operate under the influence of the spring :21 to gradually close the exhaust port 7 and open the inlet port 7. Compressed .air may now pass from the inlet port 7 to l .1 Ii

[Ell

port 7* and thence to the motor, with the effect of operating said motor to decrease the temperature in said room, whereupon said tube 10 contracts and restores the other elements of the device to the position shown in the drawings, which may be the position desired under normal conditions.

I claim:

1. The combination of a wall plate having a rearwardly extending recess, a support having a rearwardly extending chamber fitting in such recess, a plurality of ports in such chamber, a valve stem in such chamber carrying two valves, a spring tending to move said valve stem in one direction, a lever pivotally mounted at the upper end of saidsupport, a thermostatic member in operative engagement with said lever, a spring tending to maintain said lever in position against the expansive action of said thermostatic member and move said valve stem against the action of its spring, said valves controlling an inlet and an exhaust port.

2. The combination of a wall plate having a rearwardly extending recess, a support having a rearwardly extending chamber fitting in such recess a plurality of ports in such chamber, a double ended valve controlling a pair of said ports, a spring tending to move said valve to close one of said ports, a lever pivotally connected to said support, a thermostatic member carried by said support and in operative engagement with one i end of said lever, and a spring tending to hold the opposite end of said lever in engagement with the stem of said doubleended valve against the tension of the spring within such chamber for operating said valve in the other direction, and an independent needle valve controlling the amount of air passing to said chamber.

3. The combination of. a recessed wall plate having ports in the rear wall 01 such recess, a support carried thereby having a chamber adapted to fit within such recess in said wall 'plate, a valve mounted in said chamber, a spring tending to move said valve in one direction, a lever carried by the chambered support and pivotally mounted at the upper portion of" the same, a thermostatic member in operative engagement with said lever, a spring tending to maintain said lever in position to move the valve in one direction against the action of the thermostatic member, means for vertically adjusting said thermostatic member, said chamber having a plurality of ports and said valve controlling an air inlet port and an outlet port, and means mounted in one of such ports in said plate for controlling the amount of air passing to said chamber.

4. The combination of a wall plate pro vided with a recess having air ports in its rear wall, a support carried by said plate and having a rearwardly extending chamber adapted to fit within the recess in said plate, a double-ended valvevmounted in the chamber of said support, a spring tending to move said valve in one direction, shelves carried by the chambered support, a lever pivotally mounted in the upper shelf, a thermostatic member adjustably supported by the lower shelf and in operative engagement at its opposite end with said lever, a-

spring tending to maintain said lever in position to close the double ended valve in one direction against the action of the thermostatic member, said chamber having a plurality of ports alined with said air ports in said plate, and an independent needle valve for controlling the amount of air passing through such air ports to said chamber, said double-ended valve controlling the air inlet port opening into said chamber.

5. The combination of a wall plate provided with a recess having air ports in its rear wall, a bracket support carried thereby, and having a chamber adapted to fit within such recess, said chamber having a plurality of ports in alinement with such air ports in said plate, a double-ended valve controlling a pair of said ports, a spring tending to move said valve to close one of the ports, upper and lower shelyes carried by said support, a lever pivotally connected to the upper shelf, a thermostatic member carried by said support and in operative engagement with one end of said lever, an adjustable screw mounted in the lower shelf for supporting the opposite end of said member, a spring tending to hold the opposite end of said lever in engagement with the stem of the double-ended valve against the tension of the spring within said chamber for operatin said valve, and means comprising a need e valve disposed in the inlet air port for controlling the amount of air passing to said chamber.

6. The combination, in a pneumatic thermostat,of a wall plate having an apertured member connected to a source of pressure, a bracket support having a rearwardly extending chambered member fitted in and in communication with the first-named member and having a plurality of ports, a double-ended valve mounted in said. chamber and in alincment with a pair of said ports, an element controlled by a thermostatic member for moving said valve in one direction, a spring for moving the valve in the opposite direction, and a plurality of adjustable needle valves in said ported apertures comprising threaded members with pointed ends, said members being grooved for the assa e of air.

. 0 AR JES E. BONNET. 

